The missense mutation Ala458Ser was identified in a male with autistic features identified in early development, accompanied by later developing features including anxiety, pseudoseizures, ataxia, supranuclear gaze palsy, and isolated learning disabilities [3]. The authors propose that compromised FAAH2 activity and altered endocannabinoid signaling underlies the patent's phenotype.

General Comments

FAAH and FAAH2 show distinct but overlapping tissue expression patterns [4]. The absence of FAAH2 in mice and rats should be considered when extrapolating experimental findings in the endocannabinoid pathway across species.Genome wide association studies (GWAS) have identified FAAH2 as a possible candidate gene for X-linked intellectual disability [5] and autism spectrum disorders [2].